Single phase melt processed powellite (Ba,Ca)MoO4 for the immobilization of Mo-rich nuclear waste

JOURNAL OF ALLOYS AND COMPOUNDS

卷:551

Article

Brinkman, Kyle¹  Fox, Kevin¹  Marra, James¹  Reppert, Jason¹  Crum, Jarrod²  Tang, Ming³ 

[1] Savannah River Natl Lab, Aiken, SC 29808 USA

[2] Pacific NW Natl Lab, Richland, WA 99352 USA

[3] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

关键词: Waste form;    Nuclear materials;    Radiation damage;    Chemical durability;   

DOI  :  10.1016/j.jallcom.2012.09.049

来源: Elsevier

【 摘 要 】

Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO4 crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO4 and CaMoO4 were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In situ electron irradiation studies indicated that both CaMoO4 and BaMoO4 powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 x 10(13) Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m(2)). (C) 2012 Elsevier B.V. All rights reserved.

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